If patients contact the study team with symptoms suspicious for DVT or PE, they will be evaluated by a study clinician in the Thrombosis Clinic (symptoms of DVT), or referred to emergent care for evaluation (symptoms of PE). Participants' treating clinicians are also free to obtain any medically appropriate diagnostic testing for suspected DVT or PE during the follow-up period. A letter will be sent to referring physicians explaining the protocol and emphasizing that any appropriate diagnostic testing for suspected DVT or PE may be performed as clinically indicated.